Four people are reported dead after a Duke Life Flight helicopter crash in eastern North Carolina late Friday morning.

The incident happened near Belvidere in Perquimans County at about 11:45 a.m., and no cause for the crash or other information has yet been released, Fox 8 reported.

Duke Medical Center maintains two helicopters to transport critically injured or ill patients of all ages across North Carolina and neighboring states. The helicopters are available to operate 24 hours a day, 7 days a week.

Duke Health officials confirmed the crash in a statement: “With deep sorrow we can confirm that a Duke Life Flight helicopter crashed early this afternoon near Belvidere, North Carolina.”

It wasn’t clear where the helicopter was headed when it crashed, ABC 11 reported. The Highway Patrol, Sheriff’s Office and the National Transportation Safety Board are all investigating the incident.

The current Life Flight helicopters are about 5 years old, WRAL reported.

In 2000, a Life Flight helicopter crashed in a Burlington, North Carolina, neighborhood. The pilot, who was alone on board, was killed. It was later determined the pilot operated the helicopter after seeing a warning light.

Twitter users offered prayers and condolences.

Our heavy hearts & prayers are with the staff at Duke Life Flight, along with the families of those on-board. https://t.co/ZrqLeQTXRl